An electrical supply unit, such as a regulated rectifier, usually has a AC circuit-breaker positioned adjacent to the inlet (alternating voltage) and a DC circuit-breaker positioned to the outlet (direct voltage) thereof. Because the inlet and outlet of such a regulated rectifier are typically designed in a rear panel of a cabinet in which the supply unit is installed, e.g. in a position difficult to access, the unit must be taken out of the cabinet before the circuit-breakers are manually turned-on from a turned-off position caused by a current overload. Although changing the position of the circuit-breakers from the rear panel to the front panel may be helpful in the operation of the circuit breakers, a problem of electromagnetic interference inevitably produced by a long wire electrically interconnecting the rectifier and the circuit-breaker will occur.